Shoulder orthosis

ABSTRACT

A shoulder orthosis is utilized to effect relative movement between bones in a body of a patient. The orthosis includes a base section which is connected with a trunk of a patient&#39;s body, an upper arm section which is connected with an upper portion of an arm of the patient, and a lower arm section which is connected with a lower portion of the arm of a patient. An interconnection between the base section and upper arm section of the orthosis is disposed beneath an axilla between the trunk and arm of the patient. A main drive assembly is operable to rotate the lower arm section of the orthosis relative to the upper arm section of the orthosis to pivot a humerus bone in the upper arm of the patient relative to a scapula bone in a shoulder of the patient. A secondary drive assembly is operable to move the lower arm section and upper arm section relative to the base section of the orthosis to move the upper arm of the patient into alignment with the shoulder of the patient.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.10/626,951, filed Jul. 25, 2003, now U.S. Pat. No. 6,929,616, which is acontinuation of U.S. patent application Ser. No. 09/579,038, filed May26, 2000, now U.S. Pat. No. 6,599,263, which is a divisional of U.S.patent application Ser. No. 09/088,134, filed Jun. 1, 1998, now U.S.Pat. No. 6,113,562.

BACKGROUND OF INVENTION

The present invention relates to an apparatus for use in effectingrelative movement between bones in a body of a patient and, morespecifically, to an apparatus for effecting movement of bones in an armof the patient relative to a shoulder of the patient.

An orthosis for stretching viscoelastic or soft tissue in a human bodyto regain joint movement and eliminate tissue contracture is disclosedin U.S. Pat. No. 5,285,773. The apparatus disclosed in this patentincludes a pair of cuffs which are mounted on cuff arms. A driveassembly interconnects the cuff arms.

Another orthosis is disclosed in U.S. Pat. No. 5,503,619. The orthosisdisclosed in this patent includes a pair of cuffs which are connectedwith cuff arms. A drive assembly interconnects the cuff arms. Theorthosis disclosed in the aforementioned U.S. Pat. No. 5,503,619 isparticularly well adapted for use in bending a patient's wrist.

An orthosis for effecting relative movement between bones in an arm of apatient is disclosed in U.S. patent application Ser. No. 08/683,196,filed Jul. 18, 1996 by Peter M. Bonutti et al. and entitled “Orthosis”.The orthosis disclosed in the aforementioned U.S. patent applicationincludes a first cuff which grips a wrist portion of the arm of apatient. A second cuff grips an upper portion of the arm of the patient.A drive assembly is provided to rotate the first cuff about an axiswhich extends along the lower portion of the arm of the patient.Operation of the drive assembly effects pronation and suppination of thehand of the patient.

SUMMARY OF THE INVENTION

A new and improved apparatus for effecting relative movement betweenbones in a body of a patient includes a first cuff which grips a lowerportion of an arm of the patient. A second cuff grips an upper portionof the arm of the patient. A drive assembly is operable to rotate thefirst cuff and a humerus bone in the arm of the patient about a centralaxis of the humerus bone. This results in a stretching of viscoelastictissue connected with a head end portion of the humerus bone.

The extent of stretching of the viscoelastic tissue connected with ahumerus bone in the arm of the patient may be maximized by interruptingoperation of the drive assembly to allow the viscoelastic body tissue torelax. After the viscoelastic body tissue has relaxed, the driveassembly is again operated to further rotate the first cuff and furtherstretch the viscoelastic body tissue connected with the humerus bone.

A secondary drive assembly is provided to pivot the humerus bone in thearm of the patient about the head end portion of the humerus bone. Thismoves an arcuate surface on the head end portion of the humerus boneinto alignment with an arcuate surface of a glenoid cavity in a scapulabone in the shoulder of the patient. The secondary drive assembly isdisposed beneath an axilla between the trunk and arm of the patient.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing and other features of the present invention will becomemore apparent upon a consideration of the following description taken inconnection with the accompanying drawings wherein:

FIG. 1 is a schematic pictorial illustration depicting the manner inwhich a shoulder orthosis constructed in accordance with the presentinvention is connected with an arm and trunk of a body of a patient;

FIG. 2 is an illustration further depicting the construction of theshoulder orthosis of FIG. 1;

FIG. 3 is a front elevational view, taken generally along the line 3-3of FIG. 2, further illustrating the construction of the shoulderorthosis;

FIG. 4 is a schematic illustration depicting bones in an arm andshoulder of a patient;

FIG. 5 is an enlarged fragmentary front elevational view of a portion ofthe shoulder orthosis of FIGS. 1-3, illustrating the manner in which amain and secondary drive assembly are connected with cuff arms;

FIG. 6. is a fragmentary elevational view, taken generally along theline 6-6 of FIG. 3, illustrating a lower cuff arm and a portion of themain drive assembly in the shoulder orthosis of FIGS. 1-3; and

FIG. 7 (on sheet 4 of the drawings) is a fragmentary pictorialillustration of the manner in which a main gear in the drive assembly ismounted on a cuff arm of the orthosis of FIGS. 1-3.

DETAILED DESCRIPTION OF THE INVENTION

A shoulder brace or orthosis 10 (FIGS. 1-3) effects relative movementbetween bones in a body 12 (FIG. 1) of a patient 14. The shoulderorthosis 10 is used to correct misalignment or malfunction of joints ina shoulder 16 of a patient. Although the shoulder orthosis 10 has beenillustrated in FIG. 1 as being utilized in association with a left arm20 and shoulder 16, the shoulder orthosis 10 could be constructed foruse with a right arm 22 and shoulder 24 of the patient 14 if desired.

The shoulder orthosis 10 includes a base section 30 (FIGS. 1-3) which isconnected with a trunk 32 (FIG. 1) of the patient's body. The basesection 30 is connected with the trunk 32 of the patient's body at alocation beneath an armpit or axilla 34. The axilla 34 is formed at theconnection between the left arm 20 and left shoulder 16.

The shoulder orthosis 10 includes an upper arm section 38 (FIGS. 1-3)which is connected with the upper arm section 40 (FIG. 1) of the leftarm 20 of the patient. A lower arm section 42 (FIGS. 1-3) of theshoulder orthosis 10 is connected with a lower arm section 44 (FIG. 1)of the left arm 20 and a hand 46 of the patient 14.

A main drive assembly 50 (FIGS. 1-3) interconnects the upper arm section38 and the lower arm section 42. The main drive assembly 50 is manuallyoperable by the patient 14 (FIG. 1) to move the lower section 44 of thearm 20 relative to the upper section 40 of the arm 20. The main driveassembly 50 is located adjacent to an elbow 54 which interconnects theupper and lower sections 40 and 44 of the arm 20.

The main drive assembly 50 is operable to rotate bones in the arm 20 ofthe patient 14 relative to the shoulder 16 of the patient. Operation ofthe main drive assembly 50 rotates the bones in the arm 20 of thepatient 14 about a longitudinal central axis of the upper arm section40. The main drive assembly 50 can be operated in any one of twodirections to effect either internal or external rotation of a humerusbone in upper arm section 40 relative to the shoulder 16.

A secondary drive assembly 58 (FIGS. 1-3) is manually operable by thepatient 14 to align the upper section 40 (FIG. 1) of the arm 20 of thepatient 14 with the shoulder 16 of the patient. The secondary driveassembly 58 is operable in either one of two directions to effect eitherabduction or adduction of the arm 20.

The secondary drive assembly 58 is located beneath the armpit or axilla34. The secondary drive assembly is positioned between the upper armsection 40 and the trunk 32 of the patient 14. The secondary driveassembly 58 is operable to move the upper arm section 40 into alignmentwith the shoulder 16 of the patient 14. The secondary drive assembly 58is then effective to hold the upper arm section 40 in alignment with theshoulder 16.

In accordance with a feature of the present invention, the shoulderorthosis 10 (FIG. 1) obtains release of soft tissue in the shoulder 16and/or arm 20 of the patient. The shoulder orthosis 10 effectselongation of viscoelastic tissue connected with the upper arm section40 and the shoulder 16 of the patient. To effect stretching of theviscoelastic body tissue interconnecting the upper arm section 40 andshoulder 16, the main drive assembly 50 is operated to rotate thehumerus bone 62 (FIG. 4) in the upper arm section 40 relative to theshoulder 16.

Operation of the main drive assembly 50 (FIG. 1) to rotate the humerusbone 62 (FIG. 4) is interrupted when the viscoelastic body tissue hasbeen stretched to a maximum extent compatible with a patient's comfortlevel. The main drive assembly 50 is advantageously operated by thepatient 14 himself/herself so that the patient can interrupt operationof the drive assembly when required in order to maintain patientcomfort.

The main drive assembly 50 (FIG. 1) is constructed so that itcontinuously transmits force and is not operated in a reverse directionupon interruption of operation of the main drive assembly by the patient14. This results in tension being maintained in the viscoelastic bodytissue interconnecting the upper section 40 of the arm 20 of the patient14 and the shoulder 16 when operation of the main drive assembly 50 isinterrupted. When a sufficient period of time to enable the viscoelastictissue to relax has elapsed, the patient 14 again operates the maindrive assembly 50 to further stretch the viscoelastic body tissueconnected with the upper arm section 40 and shoulder 16.

The shoulder orthosis 10 effects some distraction of the joint betweenthe upper arm section 40 and shoulder 16. This distraction occurs due tothe combined weight of the shoulder orthosis 10 and the arm 20.

Bones

Some of the bones in the body 12 of the patient 14 are illustrated inFIG. 4. The trunk 32 of the patient includes a shoulder joint 66 wherethe upper arm section 40 of the patient is connected with the trunk 32of the patient. A head end portion 68 of the humerus bone 62 in theupper arm section 40 is connected with the trunk 32 at the shoulderjoint 66. A radius bone 72 and an ulna bone 74 in the lower arm section44 are connected with the opposite or lower end of the humerus bone 62.

The head end portion 68 of the humerus bone 62 is received in a glenoidcavity or fossa 80 formed in a scapula bone 82 at the shoulder joint 66.The scapula bone 82 articulates with the head end portion 68 of thehumerus and the clavicle bone 84. The clavicle or collarbone 84articulates with the sternum 86 and scapula bone 82. The scapula bone 82is connected with rib bones 88 by body tissue.

The shoulder joint 66 is somewhat similar to a ball and socket joint.The head end portion 68 of the humerus bone 62 has a configuration whichmay be considered as being hemispherical. The glenoid cavity 80 forms asocket for the head end portion 68 of the humerus bone 62. However, thesocket formed by the glenoid cavity 80 is shallow. Therefore, theglenoid cavity 80 may be considered as being a portion of a hemisphere.

It is well known that the head end portion 68 of the humerus bone 62 hasan arcuate outer side surface which is not truly hemispherical inconfiguration. Similarly, the glenoid cavity 80 has a configurationwhich may be considered as being generally ovate. Since the head endportion 68 of the humerus bone 62 and the glenoid cavity 80 are not truehemispheres, the motion which occurs between the bones at the shoulder16 during movement of the arm 20 is far more complicated than a simpleball and socket analogy.

A normal shoulder joint 66 which functions in a proper manner canaccommodate movement in all directions. In order to obtain motion of thehead end portion 68 of the humerus bone 62 without movement of thescapula bone 82 and/or clavicle bone 84, a longitudinal central axis ofthe humerus bone 62 should be aligned with a central portion of theglenoid cavity 80. When the humerus bone 62 is aligned with the glenoidcavity 80, the longitudinal central axis of the humerus bone extendsthrough or close to the center of the glenoid cavity. At this time, anarcuately curving, generally hemispherical outer side surface 92 on thehead end portion 68 of the humerus bone 62 is aligned with and isclosely adjacent to a generally hemispherical side surface 94 of theglenoid cavity 80.

It should be understood that the outer side surface 92 on the head endportion 68 of the humerus bone 62 and the side surface 94 of the glenoidcavity 80 do not have truly hemispherical configurations and do not havecenters of curvature which are exactly coincident when the head endportion 68 of the humerus bone 62 is aligned with the glenoid cavity 80.Therefore, there may be some shifting between the humerus bone 62 andthe scapula bone 82 and/or clavicle bone 84 during rotation of thehumerus bone 62 about its longitudinal central axis even though thelongitudinal central axis of the humerus bone is aligned as close as isreasonably possible with the center of the glenoid cavity 80. In orderto obtain stretching of viscoelastic body tissue interconnecting thehead end portion 68 of the humerus bone 62 and the scapula bone 82 atthe shoulder joint 66, movement of the scapula bone and/or clavicle bone84 relative to the trunk 32 should be minimized during operation of theshoulder orthosis 10.

Lower Arm Section

The lower arm section 42 (FIGS. 2, 3 and 6) of the shoulder orthosis 10is connected with the lower section 44 of the patient's arm 20 (FIG. 1).The lower arm section 42 of the shoulder orthosis 10 (FIGS. 2, 3 and 6)includes a first or lower cuff arm 102. The lower cuff arm 102 includesa straight rigid metal outer channel member 104 and a straight rigidmetal inner channel member 106. The outer and inner channel members 104and 106 are disposed in a telescopic relationship with each other andare interconnected by a fastener 108. When the fastener 108 is released,the outer channel member 104 and inner channel member 106 arelongitudinally movable relative to each other to vary the extent of thelower arm section 42 of the orthosis 10.

A hand cuff 112 is disposed on the axially outer end portion of theouter channel member 104. The hand cuff 112 is disposed on a rigidcircular metal base 114. The base 114 is fixedly connected with theouter channel member 104. A flexible hemisphere 118 (FIG. 6) isconnected to the metal base 114 and engages a palm of a hand 46 (FIG. 1)of the patient. A strap 120 (FIGS. 2, 3 and 6) engages the back of thehand 46 of the patient. The strap 120 presses the palm of the patient'shand against the hemisphere 118. By loosening the fastener 108, theposition of the hemisphere 118 relative to the inner channel member 106can be varied to adjust the lower cuff arm 102 to accommodate patientshaving arms of different lengths.

The hemisphere 118 (FIGS. 2 and 6) has a radius which is sufficient toenable a portion of the palm of the patient's hand 46 (FIG. 1) to befurther from the lower cuff arm 102 than a longitudinal central axis ofthe lower section 44 of the patient's arm 20. This results in thepatient's hand 46 being held in a relaxed, cup-shaped configuration. Byengaging the hemisphere 118, the patient's hand 46 is held againstsidewise movement and the lower arm section 44 is stabilized on thelower arm section 42 of the orthosis 10.

A first or lower cuff 126 is connected with the inner channel member 106by the fastener 108 and a second fastener 128 (FIGS. 2, 3 and 6). Thelower cuff 126 includes a flexible polymeric body section 132 which isconnected to the inner channel member 106 by the fasteners 108 and 128.The body section 132 extends part way around the lower arm section 44 ofthe patient 14 (FIG. 1). A central axis of the lower cuff 126 extendsparallel to the lower cuff arm 102 and extends through the hemisphere118 in the hand cuff 112.

A strap 134 (FIGS. 2, 3 and 6) is connected with the body section 132and extends around the lower arm section 44 of the patient. Tighteningthe strap 134 causes the body portion 132 of the first or lower cuff 126to flex inward and firmly grip the radius bone 72 and ulna bone 74 (FIG.4) in the lower arm section 44 of the patient 14 (FIG. 1). Although onespecific construction for the lower cuff 126 and hand cuff 112 isillustrated in FIGS. 2, 3 and 6, it is contemplated that these cuffscould have a different construction if desired.

In addition, the lower arm section 42 includes an elbow cuff 140 (FIGS.2, 3 and 6) which is mounted on the inner channel member 106. The elbowcuff 140 includes a base plate 142 against which the elbow 54 (FIG. 1)in the arm 20 of the patient is pressed by a strap 144. When the strap144 is tightened, the elbow 54 is firmly held against movement relativeto the lower arm section 42. The elbow cuff 140 could have a differentconstruction or could be omitted if desired.

The lower section 44 (FIG. 1) of the arm 20 of the patient 14 is firmlyheld against movement relative to the lower cuff arm 102 by threedifferent cuffs. Thus, the hand cuff 112 holds the hand 46 of thepatient 14 against movement relative to the lower cuff arm 102. Thefirst or lower cuff 126 holds the lower arm section 44 of the arm 20 ofthe patient 14 against movement relative to the lower cuff arm 102. Inaddition, the elbow cuff 140 holds the elbow 54 of the patient 14against movement relative to the lower cuff arm 102.

When the first or lower cuff 126 is connected with the lower section 44of the arm 20 of the patient 14 and the hand cuff 112 is connected withthe hand 46 of the patient (FIG. 1), a central axis of the lower sectionof the arm of the patient extends through the hemisphere 118. Force istransmitted between the hemisphere 118 and palm of the hand 46 of thepatient during operation of the shoulder orthosis 10 to effect externalrotation of the arm 20 of the patient. Similarly, force is transmittedbetween the strap 120 and the back of the hand 46 of the patient duringoperation of the shoulder orthosis 10 to effect internal rotation of thearm 20 of the patient.

Although specific constructions for the hand cuff 112, lower cuff 126and elbow cuff 140 have been disclosed herein, it is contemplated thatthese cuffs could have a different construction if desired. For example,the base plate 142 of the elbow cuff 140 could be integrally formed asone piece with the body section 132 of the lower cuff. There are manyother known cuff constructions which could be used in place of thespecific cuff constructions disclosed herein. If desired, the lower cuffarm 102 could be formed as a portion of the lower cuff 126.

Upper Arm Section

The upper arm section 38 (FIG. 1) of the shoulder orthosis 10 isconnected with the upper section 40 of the patient's arm 20. The upperarm section 38 (FIGS. 2, 3 and 5) includes a second or upper cuff arm150. The upper cuff arm 150 has a longitudinal axis which extendsperpendicular to a longitudinal axis of the lower cuff arm 102.

The second or upper cuff arm 150 includes a rigid straight metal lowerchannel member 152 (FIG. 5) and a rigid straight metal upper channelmember 154. The lower and upper channel members 152 and 154 aretelescopically adjustable relative to each other to accommodate patientshaving different length upper arm portions. Pin members 156 are providedto fixedly interconnect the lower and upper channel members 152 and 154when the second or upper cuff arm 150 has been adjusted to a desiredlength.

The upper section 40 of the patient's arm 20 (FIG. 1) is connected withthe second or upper cuff arm 150 by an upper cuff 160 (FIGS. 2, 3 and5). The upper cuff 160 has a longitudinal central axis which extendsperpendicular to and intersects a longitudinal central axis of the lowercuff 126. The upper cuff 160 includes a flexible polymeric body section162. The body section 162 is fixedly connected to a connector channel164. The connector channel 164 is fixedly connected to the upper channelmember 154 of the upper cuff arm 150.

A flexible plastic tongue 168 (FIG. 2) is connected with the bodysection 162 of the upper cuff 160. A strap 172 is connected with theopposite side of the body section 162. The flexible tongue 158 ispositioned in engagement with the upper section 40 of the patient's arm20 (FIG. 1). The strap 172 is tightened to securely grip the uppersection 40 of the patient's arm with the upper cuff 160.

Although one specific upper cuff 160 has been illustrated in FIGS. 2, 3and 5, it is contemplated that the upper cuff 160 could have a differentconstruction if desired. The upper cuff arm 150 could also have aconstruction which is different than the specific constructionillustrated in the drawings. If desired, the upper cuff 160 could beconstructed in such a manner as to enable the upper cuff arm 150 to beformed as a portion of the upper cuff.

Base Section

The base section 30 (FIGS. 1, 2 and 3) of the shoulder orthosis 10 isconnected with and is held against movement relative to the trunk 32(FIG. 1) of the patient. The base section 30 of the orthosis 10 includesa third or base cuff arm 178 (FIGS. 1, 2 and 3). The base cuff arm 178is formed by a single rigid straight metal channel member 180.

A third or base cuff 184 is slidably connected with slots in the basecuff arm 178 by suitable fasteners (not shown). The fasteners enable thebase cuff 184 to be released for movement axially along the base cuffarm 178 to position the base cuff 184 for engagement with the trunk 32of different size patients 14. The base cuff 184 includes a body section188 which is formed of a flexible polymeric material. A pad 190 isconnected with the body section 188. The body section 188 and pad 190grip the trunk 32 of the patient at a location below the arm pit oraxilla 34 (FIG. 1).

The body section 188 of the third or base cuff 184 is connected with thetrunk 32 of the patient 14 by a pair of generally horizontal straps 192and 194 (FIG. 1). The straps 192 and 194 extend around the trunk 32 ofthe patient and are connected with opposite sides of the body section188 of the base cuff 184. A shoulder strap 198 extends across theshoulder 24 to hold the body section 188 of the base cuff 184 inposition on the trunk 32 of the patient 14. The straps 192, 194, and 198cooperate with the body section 188 of the base cuff 184 to hold thebase cuff stationary on the trunk 32 of the patient 14.

The base cuff arm 178 and the second or upper cuff arm 150 areinterconnected at a pivot connection 202 (FIGS. 1, 2, 3 and 5). Thepivot connection 202 enables the upper cuff arm 150 to pivot about anaxis which extends perpendicular to and intersects longitudinal centralaxes of the base cuff arm 178 and the second or upper cuff arm 150. Thepivot connection 202 is positioned immediately beneath the armpit oraxilla 34 (FIG. 1) on the body 12 of the patient 14. The pivotconnection 202 enables the upper arm section 38, main drive assembly 50,and lower arm section 42 to be moved as a unit relative to the basesection 30 of the orthosis 10 by operation of the secondary driveassembly 58.

The base cuff 184 could have a construction which is different than thespecific construction disclosed herein. For example, the base cuff 184could be integrally formed as one piece with the upper cuff 160. Ifdesired, the base cuff arm 178 could be formed as a portion of the basecuff 184.

Secondary Drive Assembly

The secondary drive assembly 58 (FIG. 1) moves the upper arm section 40and the lower arm section 44 of the arm 20 of the patient 14 relative tothe shoulder 16. The secondary drive assembly 58 is operated to alignthe central axis of the humerus bone 62 (FIG. 4) in the upper armsection 40 with the center of the glenoid cavity 80 in the scapula bone82. The secondary drive assembly 58 may be operated by either atherapist or the patient 14. In order to promote patient confidence, itmay be preferred to have the patient 14 operate the secondary driveassembly under the instruction of a therapist.

When the central axis of the humerus bone extends through a centralportion of the glenoid cavity 80, the humerus bone 62 can be rotatedabout its central axis while the scapula bone 82 and clavicle bone 84remain substantially stationary relative to the trunk 32 of the patient14. This is because when the humerus bone 62 is aligned with the centerof the glenoid cavity 80, the central axis of the humerus bone 62extends through a center of curvature of an arcuate surface 92 on thehead end portion 68 of the humerus bone 62 and through a center ofcurvature of an arcuate surface 94 of the glenoid cavity 80.

To move the humerus bone 62 into alignment with the glenoid cavity 80,the secondary drive assembly 58 includes a rectangular tower or baseframe 210 (FIG. 5). The tower or base frame 210 extends downward fromthe pivot connection 202 between the base cuff arm 178 and the second orupper cuff arm 150. The base cuff arm 178 and second or upper cuff arm150 are pivotal toward and away from the tower 210 about the pivotconnection 202.

The tower 210 has a central axis 212 (FIG. 5) which bisects an angleformed between the longitudinal central axis of the base cuff arm 178and the longitudinal central axis of the second or upper cuff arm 150.The longitudinal central axis 212 of the tower 210 intersects andextends perpendicular to the axis about which the base cuff arm 178 andsecond or upper cuff arm 150 are pivotal at the pivot connection 202.

The secondary drive assembly 58 includes a screw 214 (FIG. 5) having acentral axis which is coincident with the central axis 212 of the tower210. The screw 214 is rotatably supported in the tower 210 by suitablebearings. The screw 214 has an external thread which engages an internalthread on an actuator block 216. The cooperation between the externalthread on the screw 214 and the internal thread between the actuatorblock 216 results in the actuator block moving toward or away from thepivot connection 202 during rotation of the screw 214 about its centralaxis.

A pair of identical links 220 and 222 (FIG. 5) extend between theactuator block 216 and the cuff arms 178 and 150. As the actuator block216 is moved axially along the screw 214, the links 220 and 222 maintainthe actuator block and the screw 214 centered midway between the cuffarms 178 and 150. Although only a single pair of links 220 and 222 areshown in FIG. 5, it should be understood that a second pair of linkshaving the same construction as the links 220 and 222 are connected withthe rear or posterior side of the actuator block 216 and the cuff arms178 and 150. The links on the posterior or rear side of the actuatorblock 216 are aligned with the links 220 and 222 on the front oranterior side of the actuator block.

A manually operable drive assembly 226 (FIG. 5) is connected with thescrew 214. The drive assembly 226 includes a worm 228 which engages agear 230. The gear 230 is fixedly connected with the screw 214. The worm228 is rotatable about an axis which extends perpendicular to coincidentcentral axes of the gear 230 and screw 214.

Manual rotation of an input member or knob 232 (FIGS. 1 and 2) rotatesthe worm 228 (FIG. 5) and the gear 230. Rotation of the gear 230 rotatesthe screw 214. Rotation of the screw 214 moves the actuator block 216either toward or away from the pivot connection 202. When the actuatorblock 216 is moved toward the pivot connection 202 by the screw 214, thebase cuff arm 178 and upper cuff arm 150 are pivoted away from eachother by the links 220 and 222. When the actuator block 216 is movedaway from the pivot connection by the screw 214, the base cuff arm 178and upper cuff arm 150 are pivoted toward each other by the links 220and 222.

The input member 232 can be manually rotated by the patient 14 to adjustthe extent of abduction of the arm 20 (FIG. 1) to a position of greatestcomfort. The position of greatest comfort will correspond to theposition in which the longitudinal central axis of the humerus bone 62(FIG. 4) is aligned with the center of the glenoid cavity 80.

The secondary drive assembly 58 (FIG. 5) is constructed so that once theangle between the upper cuff arm 150 and the base cuff arm 178 has beenadjusted by operation of the secondary drive assembly, the angle betweenthe cuff arms is maintained constant. Thus, the secondary drive assemblyis constructed so that force applied to the base cuff arm 178 and uppercuff arm 150 cannot actuate the secondary drive assembly 58 to changethe angle between the cuff arms. Therefore, once the central axis of thehumerus bone has been aligned with the center of the glenoid cavity 80by operation of the secondary drive assembly 58, the humerus bone 62 ismaintained in alignment with the center of the glenoid cavity.

The secondary drive assembly 58 has a construction which is generallysimilar to the construction of a drive assembly disclosed in U.S. Pat.No. 5,285,773. If desired, the secondary drive assembly 58 could have adifferent construction. For example, the secondary drive assembly 58could be constructed in a manner similar to that disclosed in U.S. Pat.No. 5,503,619. Of course, other known drive assemblies could besubstituted for the specific secondary drive assembly 58 illustrated inFIG. 5.

Main Drive Assembly

The main drive assembly 50 (FIGS. 2 and 5) interconnects the upper cuffarm 150 and the lower cuff arm 102. The arm 20 (FIG. 1) of the patient14 is bent at a 90° angle at the elbow 54. This allows upper section 20of the patient's arm 20 to extend along the upper cuff arm 150. Thelower section 44 of the patient's arm 20 extends along the lower cuffarm 102. The elbow 54 and adjacent portions of the patient's arm 20extend through the main drive assembly 50.

The main drive assembly 50 is operable to effect either internal orexternal rotation of the humerus bone 62 (FIG. 4) in the upper armsection 40 of the arm 20 relative to the shoulder joint 66 and scapulabone 82. Operation of the main drive assembly 50 rotates the humerusbone 62 about its longitudinal central axis. To effect rotation of thehumerus bone 62, the main drive assembly 50 pivots the lower cuff arm102 and lower section 44 of the patient's arm 20 about the longitudinalcentral axis of the humerus bone. The upper cuff arm 150 and base cuffarm 178 are stationary relative to each other and the trunk 32 of thepatient 14 during operation of the main drive assembly 50 and movementof the lower cuff arm 102.

When the main drive assembly 50 is operated to rotate the humerus bone62 about its longitudinal central axis, the secondary drive assembly 58will have previously been adjusted to align the longitudinal centralaxis of the humerus bone with the center of the glenoid cavity 80.Therefore, when the humerus bone 62 is rotated about its central axis,there is no substantial movement of the scapula bone 82 and/or claviclebone 84 relative to each other and the trunk 32 of the patient 14. Itshould be understood that the main drive assembly 50 is not operated torotate the humerus bone 62 until after the secondary drive assembly 58has been operated to position the humerus bone in alignment with theglenoid cavity 80.

The main drive assembly 50 includes a main gear or drive member 240which is fixedly connected with the lower cuff arm 102 (FIGS. 3 and 6).The main gear or drive member 240 is rotatably connected with the uppercuff arm 150. When the orthosis 10 is positioned on the arm 20 of apatient 14, in the manner illustrated in FIG. 1, the arm of the patientextends through an opening 244 (FIGS. 2 and 6) in the main gear 240.Thus, the elbow 54 (FIG. 1) is disposed in the opening 244 (FIG. 6) inthe main gear 240. The elbow cuff 140 holds the elbow in positionrelative to the main gear 240 and lower cuff arm 102.

Although the elbow 54 is shown in FIG. 1 as being disposed in theopening 244 in the main gear 240, a different portion of the arm 20 ofthe patient 14 could be disposed in the opening if desired. Furthermore,it is contemplated that the main gear 240 could be offset to one side,for example, downward, of the elbow 54 and rotatably connected with theupper cuff arm 150. If this was done, the arm 20 of the patient 14 wouldnot extend through the main gear 240 and the opening 244 could beeliminated. However, it is preferred to have the main gear 240 as closeas possible to the elbow 54 and lower cuff arm 102 to promote efficienttransfer of force between the main drive assembly 50 and the arm 20 ofthe patient 14.

The main gear 240 includes an arcuate array 248 (FIG. 6) of gear teeth250. The arcuate array 248 of gear teeth has a configuration of aportion of a circle. The central axis of the main gear 240 extendsparallel to the longitudinal central axis of the upper cuff arm 150 andis coincident with a longitudinal central axis of the upper section 40(FIG. 1) of the arm 20 of the patient. The opening 244 extends betweenopposite ends of the arcuate array 248 of gear teeth 250 to enable thearm 20 (FIG. 1) of the patient 14 to be readily moved into the openingin the main gear.

The inner channel member 106 (FIG. 6) of the lower cuff arm 102 extendsinto the opening 244. The inner channel member 106 is fixedly connectedwith the main gear 240 by suitable fasteners (not shown) which extendthrough the base plate 142 of the elbow cuff 140. The inner channelmember 106 is fixedly connected to the main gear 240 with a central axisof the inner channel member extending perpendicular to the parallelcentral axes of the main gear and upper cuff arm 150. Since the lowercuff arm 102 is fixedly connected with the main gear 240, the lower cuffarm rotates with the main gear relative to the upper cuff arm 150.

When the arm 20 of the patient 14 is positioned in the upper cuff 160,opening 244 in the main gear 240, and lower cuff 126, in the mannerillustrated in FIG. 1, the central axis of the humerus bone 62 issubstantially coincident with a central axis of the arcuate array 248 ofgear teeth 250 (FIG. 6). The central axis of the lower section 44(FIG. 1) of the patient's arm 20 intersects the central axis of theupper section 40 of the patient's arm at a right angle at the elbow 54.The intersection of the central axis of the upper section 40 and lowersection 44 of the patient's arm 20 is disposed in a central portion ofthe opening 244 in the main gear 240. When the main gear 240 and lowercuff arm 102 are rotated about the central axis of the main gear, thehumerus bone 62 (FIG. 4) in the upper section 40 of the arm 20 of thepatient is rotated about its central axis.

The main gear 240 is disposed in meshing engagement with a pinion gear256 (FIGS. 5 and 6). The pinion gear 256 is rotatably mounted on theupper cuff arm 150.

The main gear 240 is supported for rotation about the central axis ofthe opening 244 and the central axis of the upper arm section 40 of thearm 20 (FIG. 1) of the patient 14 by a positioning assembly 262 (FIG.7). The positioning assembly 262 is disposed on the anterior or backside of the main cuff arm 150. The positioning assembly 262 includes apair of guide blocks 264 and 266 (FIG. 7) which engage axially oppositesides of the main gear 240.

The guide blocks 264 and 266 are fixedly mounted on the upper cuff arm150. A pair of parallel pins 270 and 272 extend from the guide block 262into an arcuate groove 274 (FIGS. 6 and 7) formed in the main gear 240.The pins 270 and 272 extend into the arcuate groove 274 to guiderotational movement of the main gear 240 relative to the upper cuff arm150 upon rotation of the pinion gear 256 (FIG. 6). Although a groove 274(FIG. 7) is formed in only one side of the main gear 240 and pins 270and 272 extend from only the guide block 264, it is contemplated that asecond groove could be formed in the axially opposite side of the maingear 240 and be engaged by pins extending from the guide block 266 ifdesired.

It should be understood that a different mounting arrangement could beutilized for supporting the main gear 240. Thus, rather than having thearcuate groove 274, a pair of arcuate ribs could be provided on oppositesides of the main gear. These ribs would extend into arcuate tracksformed in the guide blocks 264 and 266. By having the support for themain gear 240 offset from the central axis of the main gear, it ispossible to have a portion of the arm 20 (FIG. 1) of the patient 14extend into the opening 244 (FIG. 2) through the central portion of themain gear 240. However, the main gear 240 could be offset to one side ofthe arm of the patient and could be rotatably supported at its center ifdesired.

To rotate the main gear 240 and lower cuff arm 102 relative to thesecond or upper cuff arm 150, the pinion gear 256 is rotated by a piniondrive 280 (FIG. 5). The pinion drive 280 includes a drive shaft 284(FIG. 5) which is fixedly connected with the pinion gear 256. A secondpinion gear 286 is fixedly connected to the drive shaft 284 in a coaxialrelationship with the pinion gear 256. A worm 290 is disposed in meshingengagement with the second pinion gear 286.

The worm 290 is driven by a reversible ratchet 294 (FIG. 2). Thereversible ratchet 294 is connected with the worm 290 by an input shaft296. The ratchet 294 extends in the anterior direction, that isfrontward, from the upper cuff arm 150. This enables the ratchet 294 tobe manually operated by the patient 14.

The patient operates the main drive assembly 50 by actuating the ratchet294 under the influence of force transmitted from the right arm 22(FIG. 1) of the patient to the ratchet 294. Of course, a therapist mayassist in operation of the ratchet 294 if desired. The reversibleratchet 294 can be actuated to rotate the main gear 240 in either one oftwo directions to effect either internal or external rotation of thehumerus bone 62 in the upper arm section 40 of the patient 14.

Mounting and Operation of the Orthosis

When the orthosis 10 is to be mounted on the patient 14, the straps 192,194, and 198 for the base cuff 184 (FIG. 1), a strap 144 for the elbowcuff 440, the strap 134 for the lower cuff 126, and the strap 120 forthe hand cuff 112 are all released in the manner illustrated in FIG. 2.The body section 188 of the base cuff 184 is then positioned inengagement with the trunk 32 of the patient 14. The straps 192, 194 and198 are then pulled only tight enough to loosely hold the base cuff 184in position on the trunk 32 of the patient. At this time, the connection202 between the base cuff arm 178 and the upper cuff arm 150 is disposedapproximately one inch below the arm pit or axilla 34 (FIG. 1) of thepatient 14.

Contemporaneously with positioning of the base cuff 184 on the trunk 32of the patient, the arm 20 of the patient is positioned in the uppercuff 160 and the lower cuff 126. The elbow of the patient is positionedin the elbow cuff 140. The lower cuff 126 is then tightened to grip thelower arm section 44. The elbow cuff 140 and the hand cuff 112 are thentightened. The upper cuff 160 is then tightened.

Once the various cuffs have been tightened to secure the shoulderorthosis 10 to the arm 20 of the patient, the orthosis is adjusted sothat the patient's shoulder is 30 degrees scapular plane. The upper arm40 of the patient extends forward at an angle of approximately 30°. Thestraps 192, 194 and 198 are then tightened to hold the shoulder orthosis10 firmly in place.

The input knob 232 of the secondary drive assembly 58 is then actuatedto a plane approximately 45° of abduction of the shoulder 16 of thepatient. At this time, the arm 20 is positioned in the plane of thescapula. The aforementioned steps may be performed by the patient aloneor by the patient with the help of a therapist.

Once the upper section 40 of the arm 20 of the patient has beenpositioned in alignment with the shoulder 16 by operation of thesecondary drive assembly 58, the patient operates the main driveassembly 50 to effect either external or internal rotation of thehumerus bone 62 in the upper section 40 of the arm 20. To actuate themain drive assembly 50, the patient 14 manually rotates the ratchet 294(FIG. 2).

Rotation of the ratchet 294 rotates the worm 290 and drive shaft 284.Rotation of the drive shaft 284 rotates the pinion gear 256 and maingear 240. As the main gear 240 is rotated relative to the upper cuff arm150, the humerus bone 62 is rotated about its central axis. Rotation ofthe humerus bone 62 stretches viscoelastic tissue in the shoulder joint66.

When the patient 14 has operated the main drive assembly 50 to a maximumextent compatible with comfort of the patient, operation of the maindrive assembly is interrupted. The drive arrangement between the worm290 and second gear 286 is such that force transmitted from the lowerarm section 44 through the lower cuff arm 102 to the main gear 50 isineffective to rotate the main gear relative to the upper cuff arm 150.Therefore, tension is maintained in the viscoelastic body tissueconnected with the head end portion 68 of the humerus bone 62 eventhough operation of the main drive assembly 50 is interrupted.

Immediately after operation of the main drive assembly is interrupted,the stretched viscoelastic body tissue connected with the humerus bone62 begins to relax. With the passage of a relatively short interval oftime, for example fifteen minutes, the viscoelastic body tissue willhave relaxed sufficiently to enable the patient 14 to again operate themain drive assembly 50 to further stretch the viscoelastic tissue. Asthe patient operates the main drive assembly 50 to further stretch theviscoelastic body tissue, the main gear 240 and the lower cuff arm arerotated relative to the upper cuff arm 150.

When the patient has again reached the limit of his level of comfort,operation of the drive assembly 50 is interrupted. The process ofoperating and interrupting the operation of the main drive assembly 50is repeated to obtain a gradual stretching of the viscoelastic tissueconnected with the humerus bone 62. Since the patient is in full controlof the operation of the main drive assembly 50, the patient determinesthe extent of the stretching of the viscoelastic body tissue.

When the viscoelastic body tissue has been repeatedly stretched to themaximum extent allowed by the comfort level of the patient, the shoulderorthosis 10 is removed from the body 12 of the patient 14. To do this,the direction of operation of the ratchet 294 is reversed and the maindrive assembly 50 operated to release the pressure against the lowersection 44 of the arm 20 of the patient. Once this has been done, thevarious cuffs are loosened and the orthosis 10 is removed from thepatient until the next treatment is undertaken.

CONCLUSION

A new and improved apparatus 10 for effecting relative movement betweenbones in a body 12 of a patient 14 includes a first cuff 126 which gripsa lower portion 44 of an arm 20 of the patient. A second cuff 160 gripsan upper portion 40 of the arm 20 of the patient. A drive assembly 50 isoperable to rotate the first cuff 126 and a humerus bone 62 in the arm20 of the patient 14 about a central axis of the humerus bone. Thisresults in a stretching of viscoelastic tissue connected with a head endportion 68 of the humerus bone 16.

The extent of stretching of the viscoelastic tissue connected with ahumerus bone 62 in the arm 20 of the patient 14 may be maximized byinterrupting operation of the drive assembly 50 to allow theviscoelastic body tissue to relax. After the viscoelastic body tissuehas relaxed, the drive assembly 50 is again operated to further rotatethe first cuff 126 and further stretch the viscoelastic body tissueconnected with the humerus bone 62.

A secondary drive assembly 58 is provided to pivot the humerus bone 62in the arm 20 of the patient 14 about the head end portion 68 of thehumerus bone. This moves an arcuate surface 92 on the head end portion68 of the humerus bone 62 into alignment with an arcuate surface 94 of aglenoid cavity 80 in a scapula bone 82 in the shoulder 16 of the patient14. The secondary drive assembly 58 is disposed beneath an axilla 34between the trunk 32 and arm 20 of the patient 14.

1. A shoulder orthosis for effecting rotation of an upper portion of anarm relative to a shoulder joint of a patient, the shoulder orthosiscomprising: a base section adapted to be coupled to a trunk of thepatient, the base section having a proximal end portion and a distal endportion; an upper arm section rotatably coupled to the base section atthe proximal end portion for receiving the upper portion of the arm,such that the upper arm section is configured to rotate with respect tothe base section about a connection positionable near an armpit of thepatient; and a drive assembly operatively coupled to the upper armsection, and movable with respect to the upper arm section to rotate ahumerus bone in the upper portion of the arm relative to a scapula boneof the shoulder joint.
 2. A shoulder orthosis in accordance with claim 1further comprising a lower arm section for receiving a lower portion ofthe arm, the first drive assembly operatively coupling the lower armsection to the upper arm section.
 3. A shoulder orthosis in accordancewith claim 2 wherein the lower arm section maintains the lower portionof the arm substantially orthogonal to the upper portion of the arm. 4.A shoulder orthosis in accordance with claim 2 wherein the driveassembly is manually operable by the patient to move the lower portionof the arm with respect to the upper portion of the arm to effect one ofinternal rotation of the humerus bone relative to the scapula bone andexternal rotation of the humerus bone relative to the scapula bone.
 5. Ashoulder orthosis in accordance with claim 1 wherein the drive assemblyis selectively operable to effect one of internal rotation of thehumerus bone relative to the scapula bone and external rotation of thehumerus bone relative to the scapula bone.
 6. A shoulder orthosis inaccordance with claim 5 wherein the drive assembly pivots the lowerportion of the arm about an axis of the upper portion of the arm toeffect rotation of the humerus bone relative to the scapula bone with anaxis of the humerus bone substantially aligned with a center of aglenoid cavity defined in the scapula bone to limit movement of thescapula bone relative to the trunk.
 7. A shoulder orthosis in accordancewith claim 1 wherein the first drive assembly comprises a drive gearhaving an axis of rotation aligned relative to an axis of the upperportion of the arm.
 8. A shoulder orthosis in accordance with claim 7wherein the drive gear defines an opening through which an elbowconnecting the upper portion of the arm and the lower portion of the armis positioned.
 9. A shoulder orthosis in accordance with claim 7 whereinthe drive gear comprises an arcuate array of teeth, the drive gearhaving an axis substantially coincident with a longitudinal axis of theupper arm section.
 10. A shoulder orthosis in accordance with claim 7further comprising a positioning assembly supporting the drive gear forrotation about the axis of rotation.
 11. A shoulder orthosis inaccordance with claim 10 further comprising a pinion gear rotatablymounted to the upper arm section and engaged with the drive gear.
 12. Ashoulder orthosis in accordance with claim 11 wherein the positioningassembly comprises at least one guide block coupled to the upper armsection having at least one pin extending into an arcuate groove definedwithin the drive gear to facilitate rotational movement of the drivegear relative to the upper arm section upon rotation of the pinion gear.13. A shoulder orthosis in accordance with claim 11 further comprising areversible ratchet operatively coupled to the pinion gear to rotate thedrive gear to effect one of internal rotation of the humerus bonerelative to the scapula bone and external rotation of the humerus bonerelative to the scapula bone.
 14. A shoulder orthosis in accordance withclaim 1 wherein the first drive assembly comprises a resilient memberconfigured to pivot the lower portion of the arm.
 15. A shoulderorthosis in accordance with claim 1 further comprising a second driveassembly operable to align the upper portion of the arm with theshoulder joint.
 16. A shoulder orthosis in accordance with claim 1further comprising a second drive assembly operable to be substantiallyaligned relative to an axis of the humerus bone with a glenoid cavity ofthe scapula bone.
 17. A shoulder orthosis in accordance with claim 16wherein, with the axis of the humerus bone extending substantiallythrough the center of the glenoid cavity, the first drive assembly ismovable with respect to the upper arm section to rotate the humerus boneabout the axis while the scapula bone remains substantially stationaryrelative to the trunk.
 18. A shoulder orthosis in accordance with claim1 further comprising a second drive assembly operatively coupled to theupper arm section to move the upper portion of the arm with respect tothe shoulder joint to effect one of abduction and adduction of the arm.19. A shoulder orthosis in accordance with claim 1 wherein the firstdrive assembly is operable to interrupt rotation of the humerus bonewith viscoelastic body tissue stretched to an extent compatible with acomfort level of the patient.
 20. A shoulder orthosis in accordance withclaim 19 wherein the first drive assembly maintains tension in theviscoelastic body tissue interconnecting the upper portion of the armand the shoulder joint when operation of the first drive assembly isinterrupted.
 21. A shoulder orthosis for effecting rotation of an upperportion of an arm relative to a shoulder joint of a patient, theshoulder orthosis comprising: an upper arm section for receiving theupper portion of the arm; a lower arm section for receiving a lowerportion of the arm and maintaining the lower portion of the armsubstantially orthogonal to the upper portion of the arm; a base sectionadapted to be coupled to a trunk of the patient, the base section havinga proximal end portion and a distal end portion, the upper arm sectionrotatably coupled to the base section near the proximal end, such thatthe upper arm section is configured to move with respect to the basesection about a connection positioned near an armpit of the patient; anda drive assembly operatively coupling the lower arm section to the upperarm section, and movable with respect to the upper arm section to rotatea humerus bone in the upper portion of the arm relative to a scapulabone at the shoulder joint of the patient.
 22. A shoulder orthosis inaccordance with claim 21 wherein the base section resists movementrelative to the trunk of the patient.
 23. A shoulder orthosis inaccordance with claim 21 wherein the first drive assembly is selectivelyoperable by the patient to move the lower portion of the arm withrespect to the upper portion of the arm to effect one of internalrotation of the humerus bone relative to the scapula bone and externalrotation of the humerus bone relative to the scapula bone.
 24. Ashoulder orthosis in accordance with claim 21 wherein the first driveassembly comprises a drive gear having an axis of rotation along acentral axis of the upper portion of the arm.
 25. A shoulder orthosis inaccordance with claim 24 wherein the drive gear comprises an arcuatearray of teeth forming a portion of a circle, the drive gear having anaxis substantially aligned with an axis of the upper arm section.
 26. Ashoulder orthosis in accordance with claim 24 wherein the drive gear isfixedly coupled to the lower arm section.
 27. A shoulder orthosis inaccordance with claim 24 further comprising a reversible ratchetoperatively coupled to the drive gear to rotate the drive gear to effectone of internal rotation of the humerus bone relative to the scapulabone and external rotation of the humerus bone relative to the scapulabone.
 28. A shoulder orthosis in accordance with claim 21 wherein thefirst drive assembly comprises a resilient member to pivot the lowerportion of the arm about an axis of the upper portion of the arm toeffect rotation of the humerus bone relative to the scapula bone with anaxis of the humerus bone aligned with a center of a glenoid cavitydefined in the scapula bone to limit movement of the scapula bonerelative to the trunk.
 29. A shoulder orthosis in accordance with claim21 further comprising a second drive assembly operable to align theupper portion of the arm with the shoulder joint.
 30. A shoulderorthosis in accordance with claim 21 further comprising a second driveassembly operable to align an axis of the humerus bone with a center ofa glenoid cavity defined in the scapula bone.
 31. A shoulder orthosis inaccordance with claim 21 further comprising a second drive assemblyoperatively coupled to the upper arm section to move the upper portionof the arm with respect to the shoulder joint to effect one of abductionand adduction of the arm.
 32. A shoulder orthosis in accordance withclaim 21 wherein the first drive assembly is operable to interruptrotation of the humerus bone with viscoelastic body tissue stretched toa maximum extent compatible with a comfort level of the patient.
 33. Ashoulder orthosis in accordance with claim 32 wherein the first driveassembly maintains tension in the viscoelastic body tissueinterconnecting the upper portion of the arm and the shoulder joint whenoperation of the first drive assembly is interrupted.
 34. An orthosisfor effecting rotation of a limb relative to a joint of a patient, theorthosis comprising: a base section adapted to be coupled to a trunk ofthe patient, the base section having a proximal end portion and a distalend portion; a first section rotatably coupled to the base section atthe proximal end portion for receiving a proximal portion of the limb,such that the upper arm section is configured to move with respect tothe base section about a connection positioned near an armpit of thepatient; and a drive assembly operatively coupled to the first sectionto rotate a bone relative to the joint of the patient.
 35. An orthosisin accordance with claim 34 further comprising a second section forreceiving a distal portion of the limb, the drive assembly operativelycoupling the second section to the first section.
 36. A method forassembling a shoulder orthosis, the method comprising: configuring anupper arm section for receiving the upper portion of the arm;configuring a lower arm section for receiving a lower portion of the armto maintain the lower portion of the arm substantially orthogonal to theupper portion of the arm; configuring a base section to a trunk of thepatient, the base section having a proximal end portion and a distal endportion; rotationally coupling the upper arm section to the base sectionat the proximal end portion, such that the upper arm section isconfigured to move with respect to the base section about a connectionpositionable beneath an armpit of the patient; and operatively couplingthe lower arm section to the upper arm section with a first driveassembly that is movable with respect to the upper arm section to rotatea humerus bone in the upper portion of the arm relative to a scapulabone at the shoulder joint of the patient.
 37. A method in accordancewith claim 36 further wherein configuring a base section furthercomprises configuring a base section to resist movement relative to thetrunk of the patient.
 38. A method in accordance with claim 36 whereinoperatively coupling the lower arm section to the upper arm sectioncomprises coupling the first drive assembly such that the first driveassembly is selectively operable by the patient to move the lowerportion of the arm with respect to the upper portion of the arm toeffect one of internal rotation of the humerus bone relative to thescapula bone and external rotation of the humerus bone relative to thescapula bone.
 39. A method in accordance with claim 36 furthercomprising coupling the first drive assembly to a drive gear having anaxis of rotation along an axis of the upper portion of the arm.
 40. Amethod in accordance with claim 39 wherein coupling the first driveassembly to a drive gear includes coupling a drive gear including anarcuate array of teeth forming a portion of a circle, the drive gearhaving an axis substantially aligned with an axis of the upper armsection.
 41. A method in accordance with claim 39 further comprisingfixedly coupling the drive gear to the lower arm section.
 42. A methodin accordance with claim 39 further comprising operatively coupling aratchet to the drive gear to rotate the drive gear to effect one ofinternal rotation of the humerus bone relative to the scapula bone andexternal rotation of the humerus bone relative to the scapula bone. 43.A method in accordance with claim 36 wherein coupling the first driveassembly further comprises coupling the first drive assembly including aresilient member to rotate the lower portion of the arm about an axis ofthe upper portion of the arm to effect rotation of the humerus bonerelative to the scapula bone with a an axis of the humerus bonesubstantially aligned with a center of a glenoid cavity defined in thescapula bone to limit movement of the scapula bone relative to thetrunk.
 44. A method in accordance with claim 36 further comprisingoperatively coupling a second drive assembly to the upper arm section toalign the upper portion of the arm with the shoulder joint.
 45. A methodin accordance with claim 36 further comprising operatively coupling asecond drive assembly to the upper arm section to substantially align anaxis of the humerus bone with a center of a glenoid cavity defined inthe scapula bone.
 46. A method in accordance with claim 36 furthercomprising operatively coupling a second drive assembly to the upper armsection to move the upper portion of the arm with respect to theshoulder joint to effect one of abduction and adduction of the arm. 47.A method in accordance with claim 36 wherein coupling the first driveassembly further comprises coupling the first drive assembly that isconfigured to interrupt rotation of the humerus bone with viscoelasticbody tissue stretched to a maximum extent compatible with a comfortlevel of the patient.
 48. A method in accordance with claim 47 whereincoupling the first drive assembly further comprises coupling the firstdrive assembly that is configured to maintain tension in theviscoelastic body tissue interconnecting the upper portion of the armand the shoulder joint when operation of the first drive assembly isinterrupted.